This invention concerns headlamps for motor vehicles including mounting systems for headlamps which permit adjustment in the horizontal and vertical directions for alignment of the headlamp.
Motor vehicles, including cars, trucks, and the like, are generally required to have headlamps for illuminating the road or path ahead of the motor vehicle during night travel. While it is generally desirable to provide motor vehicles with headlamps providing as much illumination as possible, safety concerns require that the illumination provided by a headlamp be controllable, at least in certain circumstances. For example, as a matter of safety to drivers of other motor vehicles which may be approaching on the same road, headlamps are required to have a "low" or "dim" setting which can be triggered either automatically or by a driver. Generally, a "low" or "dim" setting is one in which the beam of light emitted from the headlamp is directed somewhat below the horizontal and to the passenger side of the road, while a "high" or "bright" setting is one in which the beam of light is directed horizontally and straight ahead of the vehicle. Over the years, certain standards have been developed in various countries relating to the amount and direction of illumination in the presence of oncoming motor vehicles. These requirements have in turn been translated into certain requirements for lenses, reflectors, shields, and the like, all of which are well known to those skilled in the art. The term "headlight" is used herein to refer to the combination of a light source, a reflector reflecting light from the source and a lens through which the light passes, whether unitary or composite in structure. The term "headlamp" is used herein to refer to the combination of a headlight together with such supporting structure as is necessary to mount the headlight to a motor vehicle.
An aspect of the control of the illumination from a headlamp requires that the headlight be mounted to the motor vehicle in an adjustable manner such that the direction of the light emitted from the headlight can be adjusted to comply with the various regulations. A wide variety of headlight mounting schemes are known which include some adjustment feature. Typically, the mounting system employs a gimbal-like arrangement wherein a headlight is adjustable with respect to the body of the vehicle about two axes which may, but need not be, orthogonal to each other through various adjustment means. The adjusting means typically are in the form of a threaded rod or screw and appropriate follower providing for back and forth adjustment on each axis upon rotation or counter rotation of the threaded member. Such rotation or counter rotation may be caused directly with the use of a screwdriver or more indirectly through meshed gear transmission elements, rack and pinion connections, or other functionally similar operating means.
The alignment mechanisms in headlamp assemblies, particularly those involving a plurality of illumination sources, have in recent years become increasingly complex with headlamp assemblies often having nearly 75 parts and a replacement cost exceeding $125.-. Accordingly, an object of the present invention is to provide a motor vehicle headlamp assembly which avoids undue complexity and provides for a very simple adjustment of the alignment of the headlight with respect to the motor vehicle.
The headlamps employed in motor vehicles have themselves gone through considerable evolution. Initially, headlights were constructed with a housing which included a reflector directing light in a forward direction. A lens was provided usually incorporating one or more focusing elements to direct light in a preselected direction. The source of light was generally a replaceable element of one design or another. As designs progressed, these elements eventually became to be built as a single unitary sealed beam. Until recently, such sealed beam lights held a dominant position in the industry and will continue to play an important role in certain situations. It is therefore one object of the present invention to provide a mounting system for such sealed beam lights which will permit quick replacement of the light and quick alignment of the lamp.
In the very recent years, a trend away from sealed beam headlamps to both single and multiple source composite headlamps has occurred. The new composite headlamps, while considerably improved over the very early headlamps, encountered some of the same problems earlier experienced with the respect to the control of dust and moisture. Elaborate, separate systems have been developed in order to control the internal environment within the composite headlamp yet allow for the necessary venting. Accordingly, another object of the present invention is to provide a new headlamp assembly which integrally includes the required controlled venting features.
As indicated previously, composite lamp assemblies incorporate a light source which itself is removable from the reflector housing. Various means have been provided for retaining the light source within the composite headlamp. Typically, light source retaining means include separate elements fixed to an appropriate outer surface of the reflector. Such separate elements again contribute to the need for a large variety of separately manufactured parts thereby contributing to increased cost. Accordingly, it is yet another object of the present invention to provide a light source mounting arrangement which can be integral with a portion of the alignment apparatus thereby diminishing the need for separate fabricated elements.